1. Field of the Invention
The present invention relates to a shock-absorbing mechanism and medical instrument, and, more particularly to a medical instrument which is used while being inserted into a body cavity in combination with, for example, a soft endoscope, and a shock-absorbing mechanism attached to the medical instrument.
2. Background Art
As a method of performing a medical action such as an observation or a treatment on the internal organs of a human body, there is known a laparoscopic surgery which performs a surgical technique by forming a plurality of openings in an abdominal wall instead of making a large incision in an abdominal wall, and inserting treatment instruments such as an abdominoscope or clamp into the respective openings. In such a surgery, since only small openings are formed in the abdominal wall, it is advantageous in that stress on the patient is reduced.
In addition, as a method of reducing the stress to the patient, a method has been proposed for performing a surgical technique by inserting a soft endo scope through a natural opening such as patient's mouth, nose, or anus. An example of an endoscope device (medical instrument) used in such a surgical technique is disclosed in US Patent Application Laid-open No. 2005/0065397.
In the disclosed endoscope device, arm portions of which distal ends can be bent are respectively inserted through a plurality of lumens disposed in a soft inserting portion inserted through a patient's mouth. When treatment tools are respectively inserted through the arm portions, the treatment tools can be made to approach a treatment portion in different directions, and to continuously perform a plurality of surgical techniques in a state in which one endoscope is inserted into a body cavity.
In addition, in the arm portion (manipulation mechanism) disclosed in the above-described specification, four pulling wires are disposed along the arm portion so as to be located at the same interval in the circumferential direction. In the pulling wires, the proximal ends are attached to a steering opening (oscillating body) in the base end of the arm portion, and the distal ends are attached to the distal end of the arm portion. In addition, it is possible to change the direction of the treatment portion protruding from the distal end of the arm portion by curving the distal end of the arm portion in such a manner that the proximal end of the treatment tool communicating with the opening and the arm portion is inclined so as to rotate the opening with respect to the arm portion.